Superior or Sonnax servos

From what I understand there is sometimes additional machining that has to be done to the seal groove in the Sonnax servos. Is this the same for Superior brand servos? I took mine apart today and it has the "N" servo and the "F" lever. Is the r code type servo ok to use with my F lever?

I use the Superior servo and it fit/worked great with no machine work required. Frank advised me to re-use my "P" servo spring and have never had a shift issue, no flare at all and the timing of the shift seems to be spot on. If it makes a difference, I use a '76 T-bird trans case. Hope this helps.

That's good news. I'll spring for the Superior brand servo then. Is your stock servo spring heavier or lighter than the supplied spring?
One thing I did a little reading on is using a r code servo with an F lever, apparently it could crack the trans case?

The stock "P" spring was a bit heavier(larger wire diameter of the spring) than the one supplied by Superior. I just recently changed my "A" lever to an "E" lever, which should optimize shift timing and/or feel(R servo/E lever combination). I have heard the same concerns about using a larger ratio than an "E" lever with an "R" sized servo. If possible, I will check my notes and get you a wire diameter # for the servo spring. This may help:
http://www.460ford.com/forum/42-general-tech/154667-fairbanks-superior-super-servo.html

I'm not going to take a chance with the R servo and F lever. I'll do the same thing your doing and use the 1.85 E lever. From what I've read the Cobra-jet's had used the R servo and F lever and trouble with cracking the trans case, so they went with the B lever.
Thanks for the help!

All good advice already ... I'd not use the F lever with the R servo . Too much leverage IMO and risk cracking the case . The R servo, E lever is the proven setup. Although I do remember Frank mentioning he has used a D lever also

My understanding with those F or FF levers are for use with the smaller factory servos

The sonnax springs are ligter than factory. They are a .105" or .120" wire.

The factory springs are either .135" or .143/.146" wire

Some spring tensions i tested recently

Sonnax .105 spring    20LBs@ 1.84"
Sonnax .120 spring      30Lbs @ 1.84"
Factory  .135 spring     40Lbs@ 1.84"
Factory .143/.146" spring     60lbs @ 1.84"

Franks combo of the Sonnax .120" plus Dynaline #24814 = 60LBS @1.84"

Gregaust wrote:The sonnax springs are ligter than factory. They are a .105" or .120" wire.

The factory springs are either .135" or .143/.146" wire

Some spring tensions i tested recently

Sonnax .105 spring    20LBs@ 1.84"
Sonnax .120 spring      30Lbs @ 1.84"
Factory  .135 spring     40Lbs@ 1.84"
Factory .143/.146" spring     60lbs @ 1.84"

Franks combo of the Sonnax .120" plus Dynaline #24814 = 60LBS @1.84"

Greg,
This is some great info ^^, which is often hard to find for a C6. Thanks for sharing.

I should of mentioned ,Frank specifies 60LB@1.84" with his valvebody. All the testing I did was done on a valve spring tester. Came up nice, got me some good results.  Not always easy to get the heavy factory spring but his double spring setup as you see is spot on

I wasn't able to get the Dynaline spring Frank specified but got an equivalent "Century #73"  (2-1/2" x 1-3/8"x .135" .)

I measured my factory spring and it's .105 dia. So your saying the factory .105 spring plus the Dynaline #24814 will give me the pressure I need with my stock valve body?

I sourced out the Dynaline spring from Acklands, but haven't called for availability.

Never seen a factory spring @ .105" .
To get the 60LB as I tested needs the .120" spring plus the dynaline Frank mentions

That's one combo I didn't measure with a .105" spring .. Must do it

I ordered the #24814 spring and it should be here Tuesday. I wonder if I could use my .105/.135 springs and just shim them to get the 60 lbs. number? Or just try the the .105/.135 springs and see how it works. When I get the new spring I'll get them checked on a valve spring tester to see what the numbers are. Is the 1.84 an installed height?

Yes 1.84" is the installed height in the trans
The 2.5 x 1.375x .135 spring has a rate of 31.68lb at 1.84'
I used a Century Spring #73 , same specs as the #24814

Are you using Franks valvebody?  I'd estimate the double spring with the .105" spring will put you in the low 50's . That's in between the two factory springs

Maybe it's a dumb question but....

If having to modify the Sonnax unit is a common deal, why doesn't Sonnax just machine them "correctly" in the first place so their customers don't have to mess with modifying them?

You know Dave I called sonnax about this issue .Its like they don't want to hear it .They come off to me as being a little arrogant and uninterested in the c6 parts they sell .They did send me an o ring kit for their servo at no cost .I just choose to stay away from their servos .At one time TCI was offering their own r servo now on their website the one they offer appears to be a sonnax .I would imagine the superior servo is the one to go with if you wanted an aftermarket servo. Happy thanksgiving .Doug

Gregaust wrote:Yes 1.84" is the installed height in the trans
The 2.5 x 1.375x .135 spring has a rate of 31.68lb at 1.84'
I used a Century Spring #73 , same specs as the #24814

Are you using Franks valvebody?  I'd estimate the double spring with the .105" spring will put you in the low 50's . That's in between the two factory springs

No, it's a stock valvebody, D7 casting number on it. I took some of the valve body apart and discovered it doesn't even a have a shift kit installed, so I ordered a Transgo 1-2 kit for it
along with the E apply lever.

This an 11 second 3600 lb. 57 Ford. It was having a typical 2-3 shift flare and I'm hoping these mods will take care of it or at least extend the life of the trans.

DILLIGASDAVE wrote:Maybe it's a dumb question but....

If having to modify the Sonnax unit is a common deal, why doesn't Sonnax just machine them "correctly" in the first place so their customers don't have to mess with modifying them?

I've had to modify/machine every Sonnax C6 servo I have used . It is kind of sad as all the rest of their parts I use are nice . I've used several of their C4 servos and they are very nice

Need to be careful , a lot of the servos you see from different companies are rebranded Sonnax.

I've not tried the Superior but may do the next one I need

I have some info on the differences between the Superior supplied servo spring versus a factory "P" servo spring.
The Superior spring:
O.D. 1.145"
I.D. .855"
Wire dia .145"
Free length 2.20"

This Superior spring showed to have 26.7lbs preload @ 1.84"(less than half the strength/energy of the stock spring).

Stock "P" spring:
O.D. 1.25"
I.D. .966"
Wire dia .147"
Free length 2.60"

This factory spring showed 58.5lbs preload @ 1.84"

The Superior spring almost has the same wire diameter but only has to compress .36" to be at 1.84", whereas the factory spring has to compress .76" to be at 1.84", more active coils on the Superior servo 7.5 vs 6.5(P servo spring) along with a smaller O.D. causes the Superior spring to have less spring rate. SO glad Frank advised me to use the factory spring.

What would be the advantages(if any) to using a spring with 1/2 the pre-load of the stock spring?

My take on it. The only thing that the lighter springs would do is in the event of a 2-3 flare, going by the Sonnax instructions they use that as a tuning tool to slow down servo release.

The only catch there is too slow of a release will cause a bind on the 2-3

my vb's are have all the holes sized properly for shift timing , ie : no flare on the shifts and very little to no shift overlap , 35 year ! of building them
Frank

I got my trans installed and tested it on jack stands over the weekend. All seems to be good, shift points are pretty close to where they were before when left in drive. I shifted from 2 to 3 manually
at around 50 mph and it is quite noticeable in the firmness, it really does slam it in gear, but that is on jack stands. Looking forward to some dry weather, maybe around April to road test and see exactly how it performs. I ended up using my stock .105 servo spring along with the Dynaline spring which gives me around 56-58 lbs. @ 1.84 height using a bathroom scale method. I didnt use the Superior supplied spring as it cant be used with my stock spring or the Dynaline spring.

Good spring info here, thanks!

Nothing like digging up a 5 month old post. Finally got to road test my 57 with the new Superior servo and Transgo shift kit. The shifts are about 400-500 rpm higher than they were before left in drive and driving normal. The 2-3 shift is what I'm really pleased with. No more flare and thats shifting at 5500 rpm. Next Friday I'm going to try it out at the track and if I'm lucky knock off a 1/10 or 2. not sure if I mentioned before but I have also installed the E lever.

Randy

Nice Work Randy.. Good luck for next week

I used a Superior servo , stock N spring and a B lever with a low gear kit. Not yet tested but trouble free install.